Abrasive scouring powder



?atentecl Sept. 22, 1942 an r 'r a stares parent GFFiCE ABRASIVE SCGURKNG EOWDEE.

Paul W. Seder-berg, Wyandotte, Mich, assignor to The J. R. Ford Company, Wyandotte, Mich, a corporation of Michigan No Drawing. Application March 2, 1940, Serial No. 322,006

4 Claims.

effects a substantial reduction in the cost of manufacture of the product. Such products generally comprise an abrasive material and an alkaline detergent as the chief constituents. A soap or soap-like material comprises an optional ;hird ingredient.

Considerable difliculty has been experienced in ;he past in the storage or keeping qualities of abrasive scouring powders due to their tendency 0 form a relatively hard mass or cake, on standng, particularly in localities having relatively iumid or hot atmospheric conditions. Furthermore, and probably due to the fact that the lbrasive material ingredient of abrasive scouring lowders is an insoluble, silica-containing mateial such as silica flour, volcanic ash, tripoli, :owdered feldspar, pumice, pumicite and the ike, difficulty has been encountered in rinsing or washing the material from the surfate to which I: has been applied. Another problem presented n the manufacture and use of abrasive scourng powders is the control and selection of the sharpness or abrading power of the abrasive. .he abrasive functions to scrape or scratch dirt ,nd soil loose from the surface being cleaned.

Great care must be exercised in the preparation and selection of the abrasive material, lest it be ound to be too sharp and to hard so as to scratch r gouge the surface in addition to merely reaoving the dirt and soil.

When soap or a soap-like material is added 0 an abrasive scouring powder, it functions to revent the dirt and soil abraded loose from the urface to be cleaned from ire-adhering to that urface, as well as adding sudsing properties to he powder. The soap or soap-like material may onsist of either animal or vegetable oil soaps, asin soaps, blended soaps, soap powders, saponin, r the so-called wetting or sudsing agents, which re, the salts of sulphonated or sulphated organic ompounds of high molecular weight which have 3e property of decreasing the surface tension of ieir aqueous solutions and causing foaming or idsing. The cost of the soap or soap-like mate- .al is considerably higher than that of the two ther primary ingredients of the abrasive scourig powder. Hence, a reduction in the amount f soap or soap-like material required without sacrifice in the properties imparted to the :ouring powder by its presence, becomes ecoomically desirable.

I have discovered that bentonite, when added a an abrasive scouring powder, imparts unusual rid unexpected results towards curing the abovelentioned difliculties.

I have found that by adding as little as onetenth of 1% bentonite to this class of product that the keeping qualities and rinsability are greatly improved, a sharper abrasive may be used; and the bentonite may be substituted for .an equal amountof soap-like material. Also,

bentonite has very valuable detergent properties,

particularly when a product containing it is used for removing such types ofsoil as pencil marks or carbon stains from tile, porcelain, glass, or painted surfaces.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described, and par ticularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being Now, bentonite, which is a mineral clay having colloidal properties, has previously been used as a filler for soap and abrasive pastes and liquids. Such use of bentonite involved its previously known property of forming a. gelatinous mass when mixed with water. I have discovered a new and additional property of bentonite, namely, its ability to prevent caklng, hardening and setting of a powdered, technically dry mixture of silica-containing abrasive and alkali metal salt detergent material.

It is well known that silica and alkali metal hydroxides have a strong affinity to react with each other, even in the technically dry state. Such reaction is represented by the following chemical equation:

2Na0H+Si0r Na=SiO3+HzO The alkaline detergent materials used in an abrasive scouring powder comprise chiefly the alkali metal carbonates, borates, silicates and phosphates, and usually the sodium salt thereof,

such as sodium carbonate, sodiumbicarbonate, borax, tri-sodium phosphate, sodium silicates and sub-silicates, trona and the like. It is not known precisely whether these alkali metal salts used in abrasive scouring powders as the alkaline detergent material undergo a direct chemical reaction with the silica to produce silicates which have a cementing action tending to glue the particles of silicate together, or form a cake-like and hardened mass with the silica directly. Furthermore, it is not precisely known whether the silica and the alkaline material, rather than undergoing a chemical reaction, merely absorb moisture from the atmosphere or from water of hydration present in the materials, to effect a. hydraulically cementing action of the .mass. Perhaps it is a combination of these two indicated effects which has heretofore produced the dimculty of hardening and caking a mixture of silicacontaining abrasive and alkali metal salt detergent material. Conditions of relatively high atmospheric temperatures and/or humidity promote this undesired result.

The addition of bentonite in dry powdered form to the technically dry, powdered mixture of silicacontaining abrasive and alkaline material forming the basic ingredients of abrasive scouring powder, counteracts this hardening and caking tendency. The amount of such bentonite addition occurs in a critical range, being from 6 of 1% to Above this range, the addition of bentonite provides no appreciable enhancement in the desired effect.

I am unable to ascribe any exact scientific theory or principle to this new, above-described property of bentonite. It is possible, however, that the bentonite acts as an insulating medium between the particles of silica and the alkaline material, preventing a chemical reaction or physical agglomeration thereof, and possibly also absorbs any atmospheric or inherent moisture in the powder, which would otherwise effect a cementing action.

I have also discovered that such addition of bentonite remarkably improves the rinsability of the abrasive scouring powder. This effect is all the more unusual and unexpected when it is considered that the addition of bentonite to a powdere'd abrasive, such as silica flour alone, has no such efiect. Mixtures of bentonite and silica flour rinse only with great difliculty, and the time of rinsing increases as the concentration of bentonite is increased.

As a further incident to my invention, I have also discovered that the amount of soap or soaplike material, when it is used in abrasive scouring powder, can be reduced or, in effect, partially displaced by the bentonite addition, and without sacrificing the cleaning and sudsing properties of the soap or soap-like material. The bentonite, in itself, thus also acts to assist in the cleaning function of the scouring powder. The addition of the bentonite to the abrasive scouring powder has been found to impart an additional advantage, namely, that of cushioning the abrasive material. It is obvious that the abrasive or dirtscraping action of the abrasive scouring powder will be relatively more effective in proportion to the hardness and sharpness of the particles of abrasive material. However, if too hard and sharp an abrasive is used, it will not only scratch the dirt from the surface to be cleaned, but it will necessarily go the next step further and remove and damage that surface. Careful control and selection of the properties of hardness and sharpness of the abrasive material used in the scouring powder is, hence, required. But it has been found that due to the cushioning action of bentonite, that the disadvantages incident to any want of such selection or control are eliminated. The bentonite thus has the effect of tempering the action of an abrasive in the scouring powder which is too roug On the other hand, if the abrasive, in order to avoid too great a hardness or sharpness, is ground to a relatively fine size, the cost of production of the abrasive scouring powder is not only increased, but the fine dust-like particles of abrasive might prove irritating and injurious to the user, particularly, if inhaled into the respiratory system. Here again, the addition of bentonite according to the principle of my invention, in per mitting the use of a coarser ground andnon-dusting abrasive, overcomes and eliminates still further disadvantages previously encountered in the art of manufacturing abrasive scouring powder.

The addition of bentonite also imparts the physical characteristic to the abrasive scouring powder when it is in the dry form, in that it has the characteristic feel, when coming in contact with the human hands, of being smooth, soft and silky. When the abrasive scouring powder embodying my invention is mixed with water,'and hence, in the wet form, it has the desired creamy characteristics of feel and appearance and is not slimy or gritty.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or the equivalent of such be employed.

I, therefore, particularly point out and distinctly claim as my invention:

1. A substantially non-caking abrasive scouring powder, comprising a silica-containing abrasive selected from the group consisting of silica flour, volcanic ash,.=,tripoli, feldspar, pumice and pumicite and an alkali metal salt selected from the group consisting of alkali metal carbonates, bicarbonates, borates, silicates and phosphates, said abrasive and said salt forming a relatively hard, set mass or cake when normally mixed in technically dry, powdered form and subjected to atmospheric conditions of relatively high humidity and temperature, and 0.1 to 5% of bentonite present to counteract such cake-forming capacity.

2. A substantially non-caking abrasive scouring powder, comprising soap, a silica-containing abrasive selected from the group consisting of silica flour, volcanic ash, tripoli, feldspar, pumice and pumicite, and an alkali metal salt selected from the group consisting of alkali metal carbonates, bicarbonates, borates, silicates and phosphates, said abrasive and said salt forming a relatively hard, set mass or cake when normally mixed in technically dry, powdered form and subjected to atmospheric conditions of relatively high humidity and temperature, and 0.1 to 5% bentonite present to counteract such cake-forming capacity.

3. A substantially noncaking abrasive scouring powder, comprising silica flour and an alkali metal salt selected from the group consisting of alkali metal carbonates, bicarbonates, borates,

silicates and phosphates said silica flour ands-T.

said alkali metal salt forming a relatively hard, set mass or cake when normally mixed in technically dry, powdered form and subjected to atmospheric conditions of relatively high humidity and temperature, and 0.1 t0 5%-bent0nite present to counteract such cake-forming capacity.

4. A substantially non-caking abrasive scouring powder, comprising soap, silica flour and an alkali metal salt selected from 'the group consisting of alkali metal carbonates, bicarbonates, borates, silicates and phosphates, said silica flour and said alkali metal salt forming a relatively hard, set mass or cake when normally mixed in technically dry, powdered form and subjected to atmospheric conditions of relatively high humidity and temperature, and 0.1 to 5% bentonite present to counteract such cake-farming capacity.

PAUL W.'SODERBERG. 

